US6157641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiprotocol packet recognition and switching
Assignee: Cisco Technology Inc
•
Filing: 1997-08-22
•
Granted: 2000-12-05
•
Expires: 2017-08-22
Abstract
Abstract The invention provides a method and system for identifying header information in a packet header, and for switching (and otherwise operating) on the packet in response thereto. A first set of header information recognizers operate in parallel on selected words of the packet header so as to recognize a header format for the packet header and to determine header information in response to that header format. A second set of header information recognizers operates on the header information to select a set of words from the packet header which are used for lookup for treatment of the packet. The same or similar header information is located in the packet header responsive to information which determines an encapsulation type for the packet, such as packets which use the IP version 4, IP version 6, or IPX protocols. The header information can include the destination address for the packet, or some combination of the destination address and additional information; the additional information can include the sending address, the input interface, a number of bits matched for the destination address, or some combination thereof.
Inventors
- 👤 Bruce A. Wilford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:36
CPC Classifications
H; H04; H04L; H04L45/00; H04L45/60; H04L45/52; H04L49/00; H04L49/60; H04L49/602; H04L9/00; H04L9/40; H04L2212/00; H04L69/00; H04L69/22
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
109 words
A method, including the steps of: receiving a packet header including header information at selected words of the packet header; applying in parallel a first set of words of said packet header to a first plurality of header information recognizers, and selecting a second set of words of said packet header in response thereto, said second set of words being a subset of said first set of words; applying in parallel said second set of words to a second plurality of header information recognizers, and selecting a packet treatment identifier in response thereto; and using said packet treatment identifier to access a memory having information regarding treatment of packets.
Claim 2
Independent Claim
109 words
A method, including the steps of: receiving a packet header including header information at selected words of the packet header; applying in parallel a first set of words of said packet header to a first plurality of header information recognizers, and selecting a second set of words of said packet header in response thereto, said second set of words being a subset of said first set of words; applying in parallel said second set of words to a second plurality of header information recognizers, and selecting a packet treatment identifier in response thereto; and using said packet treatment identifier to access a memory having information regarding treatment of packets.
Claim 3
Dependent Claim
42 words
A method as in claim 1, wherein each said header information recognizer includes a first word having a value for matching to a corresponding word of said packet header; and a second word having an instruction for execution responsive to said matching.
Claim 4
Dependent Claim
23 words
A method according to claim 1, including the step of transforming said second set of words into a compact set of header information.
Claim 5
Dependent Claim
35 words
A method as in claim 1, wherein said header information includes a destination address for the packet plus either a sending address, an input interface, or a number of bits matched for the destination address.
Claim 6
Dependent Claim
20 words
A method according to claim 1, wherein said first plurality of header information recognizers comprise a plurality of encapsulation recognizers.
Claim 7
Dependent Claim
22 words
A method according to claim 1, wherein said second set of words is selected at least in part by an encapsulation multiplexer.
Claim 8
Dependent Claim
21 words
A method according to claim 1, wherein said second plurality of header information recognizers comprise a plurality of longest match recognizers.
Claim 9
Dependent Claim
24 words
A method according to claim 1, wherein said packet treatment identifier is selected at least in part by a plurality of longest match multiplexers.
Claim 10
Independent Claim
138 words
An apparatus for accessing information regarding treatment of packets, each packet having a packet header, each packet header including header information at selected words of said packet header, said apparatus comprising: a first plurality of header information recognizers to which a first set of words of said packet header is applied in parallel; and a second plurality of header information recognizers to which a second set of words is applied in parallel, said second set of words selected in response to recognition by said first plurality of header information recognizers, said second set of words being a subset of said first set of words; and a memory having information regarding treatment of packets which is accessed using a packet treatment identifier, said packet treatment identifier selected in response to recognition by said second plurality of header information recognizers.
Claim 11
Independent Claim
138 words
An apparatus for accessing information regarding treatment of packets, each packet having a packet header, each packet header including header information at selected words of said packet header, said apparatus comprising: a first plurality of header information recognizers to which a first set of words of said packet header is applied in parallel; and a second plurality of header information recognizers to which a second set of words is applied in parallel, said second set of words selected in response to recognition by said first plurality of header information recognizers, said second set of words being a subset of said first set of words; and a memory having information regarding treatment of packets which is accessed using a packet treatment identifier, said packet treatment identifier selected in response to recognition by said second plurality of header information recognizers.
Claim 12
Dependent Claim
41 words
An apparatus according to claim 9, wherein each said header information recognizer includes: a first word having a value for matching a corresponding word of said packet header; and a second word having an instruction for execution responsive to said matching.
Claim 13
Dependent Claim
21 words
An apparatus according to claim 9, wherein said second set of words is transformed into a compact set of header information.
Claim 14
Dependent Claim
35 words
An apparatus according to claim 9, wherein said header information includes a destination address for the packet plus either a sending address, an input interface, or a number of bits matched for the destination address.
Claim 15
Dependent Claim
20 words
An apparatus according to claim 9, wherein said first plurality of header information recognizers comprise a plurality of encapsulation recognizers.
Claim 16
Dependent Claim
27 words
An apparatus according to claim 9, further comprising an encapsulation multiplexer, wherein said second set of words is selected at least in part by said encapsulation multiplexer.
Claim 17
Dependent Claim
21 words
An apparatus according to claim 9, wherein said second plurality of header information recognizers comprise a plurality of longest match recognizers.
Claim 18
Dependent Claim
32 words
An apparatus according to claim 9, further comprising a plurality of longest match multiplexers, wherein said packet treatment identifier is selected at least in part by said plurality of longest match multiplexers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-12-05 | 2004-06-05 | 2004-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-05 | 2008-06-05 | 2008-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-05 | 2012-06-05 | 2012-12-05 | $7700.00 | Window Closed / Lapsed |